JPH0294887A - Electronic still camera device - Google Patents

Abstract

PURPOSE:To attain easy and accurate white balance adjustment with simple constitution by interposing a white transparent body for adjusting white balance adjustment between a pickup lens and a CCD in interlocking with the operation of a release switch and interposing an exposure control section in place of the white transparent body in this state. CONSTITUTION:When the release switch is operated, a motor 30 is driven and a turning disk 35 is driven counter clockwise and white diffusion plates 33e, 34e of both aperture blades 33, 34 are overlapped. In this case, the CCD applies pickup and white balance adjustment is attained. Then the motor 30 is driven, the turning disk 35 is driven clockwise and the turning position of the turning plate 35 is set so that an optimum aperture diameter L is formed by the notch 33d of the aperture blade 33 and the notch 34d of the aperture blade 34 to pick up an actual still picture.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic still camera device that captures and records still images using a solid-state imaging device (hereinafter referred to as CCD), and particularly relates to The present invention relates to automatic white balance adjustment.

(Prior Art) As is well known, in recent years CCDs for television cameras have been developed.
As the performance of two-dimensional image sensors (two-dimensional image sensors) continues to improve, this CC
Camera-integrated VTRs (video tape recorders) using D are widespread in the market.

-/17', an electronic still camera device that uses this CCD to magnetically record still images on a 2-inch magnetic floppy disk has been standardized, and products are being sold by various companies.

This electronic still camera device converts optical images into electrical signals and records them, allowing for immediate playback. Unlike conventional silver halide film, this electronic still camera device can also perform image processing and transmission, so it can be used for a wide range of systematic applications. It becomes possible.

FIG. 5 shows such a conventional electronic still camera device. That is, numeral 11 in the figure is a camera housing, and a finder section 12 is provided on the upper part of the camera housing. Furthermore, a lens barrel 14 that supports a photographic lens 13 is provided at approximately the center of the front surface of the camera housing 11. The amount of photographic light transmitted through the photographic lens 13 is controlled by an exposure control mechanism 16 controlled by a drive lens 15, and then passes through an optical low-pass filter I7 to a CCD II.
I is irradiated onto I, a subject image is formed there, and photoelectric conversion is performed.

The still image electrical signals obtained from the COD 18 in this way are supplied to the color separation circuit 19, where each color signal R
, G, and B, and then separated into a luminance signal Y and a color difference signal C by the signal processing circuit 20. In this case, in order to correct the fact that the output levels of color signals R, G, and B change even for the same subject depending on the color temperature of the light source that illuminates the subject, the white balance sensor 21 that detects the color temperature of the light source The R, G, and B levels of the light source are detected and input into the microcomputer 22, and the microcomputer 22 outputs the color signal R1G of the color separation circuit 19.
, B output level gain control is performed.

Here, the luminance signal Y separated by the signal processing circuit 20 is
and color difference signal C are respectively supplied to frequency modulators 23 and 24, frequency modulated, frequency multiplexed, and then sent to amplifier 2.
5 to the magnetic head 26. On the other hand, a magnetic floppy disk 27 is in sliding contact with this magnetic head 2B. This magnetic floppy disk 27 is rotated by a motor 29 being driven by a drive signal generated from a drive circuit 28 in response to a command from a microcomputer 22, and the still image formed on the CCD 18 is It is recorded on the floppy disk 27.

However, such conventional electronic still camera devices detect the color temperature of the subject using the white balance sensor 21, but since the output of the sensor 21 itself is small, it is necessary to increase the gain. However, the level of the detection signal output from the white balance sensor 21 to the microcomputer 22 may change due to temperature changes, changes over time, etc., resulting in a problem that accurate white balance adjustment cannot be performed.

Further, the white balance sensor 21 is connected to the camera housing 11.
Since it is located at a distance from the photographic lens 14 within the camera, it cannot necessarily be said that it measures the color temperature of the light source itself illuminating the subject, and in this respect as well, accurate white balance adjustment cannot be performed. The current situation is that we cannot say that there is.

In this regard, with television cameras that shoot video, the user can adjust the white balance, that is, R, G, It is possible to adjust the gain, but with an electronic still camera device, each time a photograph is taken, for example, a white cap is placed over the photographing lens 13 and the shutter is released to release the white balance 17! J! 1, the adjustment work is extremely complicated and the handling becomes inconvenient for the user.

(Problems to be Solved by the Invention) As described above, with conventional electronic still camera devices, it is difficult to accurately adjust the white balance.
In addition, in order to perform accurate white balance adjustment,
This has the problem that adjustment work becomes complicated.

Therefore, the present invention was made in consideration of the above-mentioned circumstances (i1), and an object of the present invention is to provide an extremely good electronic still camera device that has a commercially available configuration and can easily perform accurate white balance adjustment. .

t11 of invention E] (Means for solving the problem) An electronic still camera device according to the present invention includes a photographing lens, an exposure control section that controls the amount of photographic light transmitted through the photographic lens, and an exposure control section that controls the amount of photographic light transmitted through the photographic lens. A CCD 1, on which the photographing light that has passed through the section is imaged and performs photoelectric conversion;
The present invention is intended for devices equipped with a signal processing and recording section that performs predetermined signal processing on electrical signals generated and records them on a recording medium.

Then, in conjunction with the operation of the release switch, a white transparent body for white balance adjustment is interposed between the photographing lens and the CCD in place of the exposure control section, and a signal processing recording section is used based on the electrical signals obtained from the CCD. White balance:
A-adjustment is performed, and in this state, an exposure control section is interposed between the photographing lens and the CCD in place of the white transparent body.

(Function) According to the above configuration, in conjunction with the operation of the release switch, white balance adjustment is performed by interposing a white transparent body for white balance adjustment between the photographing lens and the CCD, and this state is Therefore, instead of a white transparent material, an exposure control section is interposed between the photographing lens and the CCD, so that white balance adjustment is performed automatically every time a photograph is taken. This allows for accurate white balance adjustment.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an exposure control mechanism interposed between a photographic lens and a CCD. This exposure control mechanism consists of a support plate 31 to which a motor 3o is attached, and a presser plate 3.
It has a structure in which aperture blades 33 and 34 are sandwiched between the two.

A rotary plate 35 is attached to the shaft of the motor 30, and a pair of pins 35a and 35b are formed protruding from the rotary plate 35 with the center of rotation interposed therebetween.

Of these, the pin 35a is inserted through a long hole 34a formed in the aperture blade 34 and loosely inserted into an arc-shaped long hole 32a formed in the temporary presser foot 32. Further, the pin 35b is inserted through a long hole 33a formed in the aperture blade 33, and is inserted into the presser plate 3.
It is loosely inserted into an arcuate long hole 32b formed in 2.

Here, through holes 31a and 32c are formed in the support plate 31 and the presser plate 32, respectively, for guiding photographing light transmitted through a photographing lens (not shown) to the COD.

Among these, pins 31b and 31e for position regulation are formed projectingly above and below the through hole 31a of the support plate 31 in the drawing, respectively.

The pin 31b is inserted into the long holes 33b and 34b formed in the aperture blades 33 and 34, respectively, and is inserted into the through hole 32d formed in the holding plate 32 (15a). Further, the pin 31e is connected to a long hole 33 formed in the aperture blade 33.34.
c.

34e respectively, and are fitted into the through holes 32cl formed in the presser plate 32.

Here, the aperture blade 33 is formed with a pentagonal Q-shaped notch 33d that constitutes an exposure control section, and a white diffuser plate 33c is installed. In addition, the aperture blade 3
A notch 34d constituting an exposure control section is formed in 4, and a white diffusion plate 34e is installed.

The operation of the above configuration will be described below. First, FIG. 2(a) shows a standby state of the electronic still camera device before operating a release switch (not shown). That is, the rotational position of the rotary plate 35 is set so that the minimum aperture diameter L min is formed by the notch 33 (1) of the aperture blade 33 and the notch 34d of the aperture blade 34.

Then, when the release switch is operated, the motor 30
is driven, the rotating plate 35 is rotated clockwise in FIG. 2(a), and both aperture blades 33 are rotated as shown in FIG.
．． The 34 white diffusion plates 330 and 34c come to overlap. At this time, the COD captures an image and white balance adjustment is performed.

Thereafter, the motor 30 is driven, and the rotary plate 35 is rotated as shown in FIG.
b) It is rotated in the middle clockwise direction, and as shown in FIG. The rotational position of the rotary plate 35 is set in this way, and an actual still image is taken.

FIG. 3 shows a control means for automatically adjusting white balance using the exposure control mechanism as described above. That is, the exposure control mechanism 38 shown in FIG. 1 is interposed between the photographing lens 36 and the CCD 37. In the standby state where the release switch 39 is not operated yet, the CPU (central processing circuit) 40
The motor 30 is controlled by the driver 41 so that the exposure control mechanism 38 is in the state shown in FIG. 2(a).

When the release switch 39 is operated in this state, the shutter trigger signal from the release switch 39 is sent to the CPU.
40. Then, the CPU 40 controls the motor 30 via the driver 41, and the exposure control mechanism 38 controls the second motor 30 via the driver 41.
Control is performed so that the state shown in Figure (b) is achieved. For this reason,
The CCD 37 includes a photographing lens 3G and a white diffuser plate 33c.
, 34c are stored.

At this time, the charge accumulated in the CCD 37 is transferred to the CPU 40.
An output pulse from a pulse generator (hereinafter referred to as SSG) 42 driven by a command from the SSG is extracted as a continuous one-screen signal, amplified by an amplifier 43, and then supplied to a color separation circuit 44. In this color separation circuit 44,
Gain for independently extracting the temporally sampled color signals R, G, and B determined by the color filter array of the CCD 37 and performing white balance adjustment:
1! Processing such as J adjustment and gamma correction is performed.

In this case, white balance gain adjustment is performed by CPU4.
The set value is output from 0 as digital data, and these data are converted into analog signals by D/A (digital/analog) converters 45 to 47 and supplied to the control input terminals WBR, WBC, and WBB of the color separation circuit 44. It is done by doing.

At the time of the first image capture, the white balance gain is set in the CPU 40 as an initial setting value.
Based on this set value, the color separation circuit 44 outputs the color signals R, G,
B is taken out individually. After that, these color signals R, G
, B are combined into one system by the multiplexer 48, and the A/D
The signal is converted into digital data by an (analog/digital) converter 49, and separated into a luminance signal Y and a color difference signal C by a signal processing circuit 50.

Here, the signal processing circuit 50 outputs digitized color signals R, G, and B to adders 51 to 53, respectively. These adders 51 to 53 receive digitized color signals R and G under the control of an adder controller 54.
, B are added in level and output to the CPU 40. In this case, the adders 51 to 53 serially output, for example, only the upper 8 bits of the addition results to the CPU 40 to ensure accuracy.

Now, since the optical image transmitted through the white diffusers 1i33e and 34c is captured, the adders 51 to 53
The addition results of each color signal R, G, and B obtained from the above should be at the same level, but if the color humidity of the light source does not correspond to the initial setting white balance gain described above, the addition result are not consistent.

Therefore, a conversion table between color signal R, G, and B levels and white balance adjustment gain level is provided in the CPU 40, and data for white balance gain adjustment is created based on the input color signal R, G, and B levels. D/A converter 4
5 to 47, and the white balance is adjusted.

When the automatic white balance adjustment is completed as described above, the CPU 40 controls the motor 3 via the driver 41.
0, as shown in FIG. 2(c) by the exposure control mechanism 38,
Control the exposure so that it is optimal for the subject. Therefore, the color separation circuit 44 outputs color signals R1G and B that have undergone accurate white balance adjustment, and finally the signal processing circuit 50 outputs a luminance signal Y and a color difference signal C. It is recorded on floppy disks, etc.

Therefore, according to the configuration of the above embodiment, in conjunction with the operation of the release switch 39, the photographing lenses 3G and C
After automatically adjusting the white balance by interposing white diffusers 33c and 34c for white balance adjustment between the CCD 37 and the CCD 37, an exposure control section 38 is interposed between the photographing lens 36 and the CCD 37 to adjust the exposure. Since the white balance adjustment is automatically performed each time a photograph is taken, it is possible to easily and accurately adjust the white balance with a simple component configuration.

In addition, a photographic lens 3B and white diffuser plates 33e and 34
Since the white balance is adjusted based on the photographing light that has passed through e (using the output of the CCD 37), there is no positional shift relative to the subject compared to the conventional method using the external sensor 21, and the subject is In addition to being able to accurately detect the color temperature of the irradiating light source, there is no error due to the difference between the sensor's color filter and the CCD's color filter, and there is no effect of the sensor's output fluctuation, etc. Balance can be adjusted.

Further, in the above embodiment, the two aperture blades 33 and 34 of the exposure control mechanism 38 are each provided with white diffusion tlZ33c.

34e was installed. However, this may be provided only on either one of the aperture blades 33 or 34.

FIG. 4 shows another example of the exposure control mechanism.

That is, along the periphery of the disk 56 having the rotating shaft 55, aperture holes 57 each having a different diameter are arranged, and
A white diffuser plate 58 is provided, and the disc 5 is attached to the lens barrel 59.
It can be handled in the same manner as in the above embodiment by rotating 6 articulately.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an extremely good electronic still camera device that has a simple configuration and can easily perform accurate white balance adjustment.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of an electronic still camera device according to the present invention, and FIG. 2 is an exploded perspective view showing the configuration of an exposure control mechanism, and FIG. 2 is a front view illustrating the operation of the exposure control mechanism. Fig. 3 is a block diagram showing a control means for automatically adjusting white balance, Fig. 4 is a plan view showing another example of the exposure control mechanism, and Fig. 5 is a side view showing a conventional electronic still camera device. It is. 11... Camera housing, 12... Finder section, 13
...Photographing lens, 14...Lens barrel, 15...
Drive motor, 16... Exposure control mechanism, 17... Optical low pass filter, 18... CCD, 19... Color separation circuit, 20... Signal processing circuit, 21... White balance sensor, 22...Microcomputer,
23.24...Frequency modulator, 25...Amplifier, 2
6...Magnetic head, 27...Magnetic floppy disk, 28...Drive circuit, 29.30...Motor, 3
1... Support plate, 32... Holding plate, 33.34...
Aperture blade, 35... rotation speed, 3G... photographing lens,
37... CCD, 38... Exposure control mechanism, 39...
・Release switch, 40...CPU, 41...Driver, 42...SSG, 43...Amplifier, 44...
...Color separation circuit, 45-47...D/A converter, 48
... Multiplexer, 49 ... A/Da converter, 50
... Signal processing circuit, 51-53 ... Adder, 54.
...Adder controller, 55... Rotation axis, 56...
・Disk, 57... Aperture hole, 58... White diffuser plate, 5
9... Lens barrel. 1 Figure applicant's agent Patent attorney Suzue Takehiko Kasumi Zugyozu

Claims (1)

[Claims] A photographic lens, an exposure control unit that controls the amount of photographic light that has passed through the photographic lens, a solid-state image sensor that forms an image of the photographic light that has passed through the exposure control unit, and performs photoelectric conversion; In an electronic still camera device, the electronic still camera device is equipped with a signal processing and recording section that performs predetermined signal processing on an electric signal received by the camera and records it on a recording medium. a first means for interposing a white transparent body for white balance adjustment in place of the exposure control section; and a first means for interposing the white transparent body between the photographing lens and the solid-state image sensor; a second means for performing white balance adjustment of the signal processing and recording section based on the electric signal obtained from the solid-state image sensor in the state where the white balance adjustment is completed by the second means; An electronic still camera device comprising: third means for interposing the exposure control unit instead of the white transparent body between the photographing lens and the solid-state image sensor.